Abstract: The invention comprises three parts: The first parts provides a miniaturized functional optical module, which is provided with a lens-exchange type collimator enabling rapid and easy exchange of an optical functional component and/or lenses and being compact in size and excellent in durability.

Abstract: An improved optic attenuator controllably filters an optical signal after the signal has been expanded and collimated. The optical signals are preferably expanded and refocused by a single GRIN lens, the signal passing through a variable filter between the GRIN lens and a reflector, and again between the reflector and the GRIN lens. Both the input and output fibers can be held within a single sleeve in alignment with the GRIN lens. The amount of attenuation can be indicated by a potentiometer.

Abstract: The present invention relates to an instrument and method of aligning a collimator. The instrument includes a frame base, a clamp, a first axis stage, a second axis stage, and a rack. A ferrule grasping a fiber therein is inserted in a glass tube, and the glass tube is secured to the frame base by the clamp. A pinion is fixedly mounted on one end of a GRIN lens, which is inserted in the glass tube, and engaged with the rack. The first axis stage moves the GRIN lens along the cylindrical axis of the glass tube, and the second axis stage rotates the GRIN lens around the cylindrical axis of the glass tube. When a light beam emitted from the collimator reaches the maximum intensity, the instrument of the invention accomplishes the alignment of the collimator.

Abstract: An optical collimator is provided for ready fitting to an optical device with precise optical alignment, to obviate the need for adjusting the collimator during assembly to the optical device to compensate for a translational offset and an angular deviation. In an embodiment, the collimator has a sleeve with an outer cylindrical surface that is concentric with the output optical path, which has a translational offset and an angular deviation with respect to the collimator axis. A method is provided for making such a collimator for ready fitting to an optical device with precise optical alignment. In an embodiment, a portion of an outer sleeve of the collimator is removed according to the offset and the deviation to form an outer cylindrical surface that is centered about an axis which coincides with the optical path emanating from the collimator, to allow the collimator to be readily fitted to an optical device.

Abstract: An optical isolator includes a first collimator, a second collimator and an isolation assembly arranged between the collimators. The first collimator includes a first capillary retaining an input fiber and a first GRIN lens received and retained in a first glass sleeve. The isolation assembly includes two birefringent crystal wedges with an optical rotator interposed between the birefringent crystal wedges. A magnetic ring receives and retains the birefringent crystal wedges and the optical rotator together. The second collimator includes a second capillary retaining an output fiber and a second GRIN lens which are received and retained in a second glass sleeve. A first stainless steel sleeve receives and retains the first glass sleeve and the isolation assembly together while a second stainless sleeve is fit over the second collimator. Apertures are defined in the first stainless steel sleeve.

Abstract: A miniaturized and easy-assembling optical circuit module includes optical signal emitting means for emitting an optical signal, a sleeve having an end surface, an optical device having a reflection surface, which contacts the end surface, and a lens located between the optical signal emitting means and the optical device. The lens converts the optical signal to a collimated optical signal, which is emitted to the optical device, reflected by the reflection surface and then converged by the lens to generate a converged light signal. The module further includes optical signal receiving means for receiving the converged light signal. The lens is fixed in the sleeve such that the focal point of the lens is aligned with the reflection surface. The optical signal emitting means and the optical signal receiving means are fixed in the sleeve such that the converged light signal is coupled into the optical signal receiving means.

Abstract: Disclosed is an optical fiber collimator including a single-mode fiber and a graded-index multi-mode fiber. The graded-index multi-mode fiber is spliced with the single-mode fiber and has a predetermined length so as to collimate light rays. The waveform of the light rays in the graded-index multi-mode fiber has a period P during the transmission and the length of the graded-index multi-mode is substantially 0.25×N×P, wherein N is a positive odd number.

Abstract: A GRIN fiber lens has a silica-glass core whose refractive index has a radial profile. The profile has a radial second derivative whose average magnitude in the core is less than about 1.7×10−6 microns−2 times the value of the refractive index on the axis of the GRIN fiber lens.

Abstract: An apparatus and method of building multiple-port optical devices characterizes optical filters according to a desired angle of incidence. Fiber ferrules are manufactured to precisely position at least two pairs of optical fibers inside the ferrules. The fiber ferrules are then characterized according to the distance between the fiber cores of the fiber pairs (i.e. the separation distance). The filters and the fiber ferrules are matched according to predetermined tolerances. The filter, or other optical element, is optically aligned with each pair of optical fibers and bonded into place. Light signals, such as DWDM signals, are then transmitted through the devices and the single filter or optical device operates on the multiple signals.

Abstract: An improved wavelength division multiplexing device is disclosed. The improved wavelength division multiplexing device has a diffraction grating for combining a plurality of monochromatic optical beams into a multiplexed, polychromatic optical beam. The improvement in the improved wavelength division multiplexing device is the use of a homogeneous refractive index collimating/focusing lens for collimating the plurality of monochromatic optical beams traveling along a first direction to the diffraction grating, and for focusing the multiplexed, polychromatic optical beam traveling along a second direction from the diffraction grating, wherein the second direction being substantially opposite the first direction.

Abstract: An optical device is provided, which includes optical fibers and rod lenses with their optical axes all being allowed to coincide, particularly, through optimization of the angles of faces of the rod lenses processed to have slopes, wherein the path of a center light ray entering an input fiber is allowed to coincide with the optical axes.

Abstract: The optical device, capable of reducing reflectance over a wide wavelength region, has an anti-reflection film interposed between a rod lens and an optical fiber. The anti-reflection film includes a plurality of laminas. The refractive index of the lamina contiguous to the optical fiber is matched with that of the optical fiber, while the refractive index of the lamina contiguous to the rod lens is matched with that of the rod lens. The laminas are set to have refractive indices such that the refractive index of the optical fiber and that of the rod lens are connected to each other to form a smooth curve.

Abstract: A method for manufacturing an optical device, and an optical apparatus are disclosed. In the manufacturing method an optical component is disposed proximate a collimator lens such that a reflecting portion of the optical component is disposed on a focal plane of the collimator lens. The reflecting portion of the optical component is configured to reflect at least a portion of an optical signal from a launch fiber back towards a receiving fiber that is disposed on the same side of the optical component as the launch fiber. The optical component is passively aligned at an angular orientation with respect to the focal plane of the collimator lens. The apparatus includes an optical component, a collimator lens, and a spacer disposed between the component and the collimator lens.

Abstract: A method and system for providing an optical switch is described. The method and system include providing a triple fiber collimator, a beam deflector and a reflector. The triple fiber collimator is for receiving an optical signal from a first fiber and outputting the optical signal to a second fiber or a third fiber. The beam deflector has a first portion and a second portion. The beam deflector resides between the reflector and the triple fiber collimator. The optical signal travels through the first portion of the beam deflector, is reflected by the reflector and is output over the second fiber when the beam deflector is in a first position. The optical signal travels through the second portion of the beam deflector, is reflected by the reflector and is output over the third fiber when the beam deflector is in a second position.

Abstract: A variable optical attenuator (99) comprises a holder (4), a rotatable mechanism (5), a refractor (6), an input port (2) and an output port (3). The input port and the output port are engaged with corresponding upright beams (42, 43) of the holder, which hold the input port and the output port in alignment with each other. The refractor is mounted on the rotatable mechanism by adhering to or soldering on a groove (52) of the rotatable mechanism, wherein the rotatable mechanism mates with a through hole (46) of the holder to make the center of the refractor and the optical axis of input and output collimators (22, 32) of the input and output ports in line.

Abstract: An optical collimator comprises an optical fiber, a capillary, a GRIN lens and a glass tube. A bore is defined in the capillary. A conical depression is defined in an end of the capillary and in communication with the bore. The optical fiber is retained in the bore of the capillary. An end of the capillary is bonded with an end of the GRIN lens. The capillary and the GRIN lens are encased in the glass tube.

Abstract: An optical collimator comprises an optical fiber (210), a ferrule (220), a GRIN lens (230), a metal sleeve (240), and an outer metal tube (250). The optical fiber has an exposed end which is inserted into the ferrule and glued thereinto. The GRIN lens is glued into the sleeve. Opposite ends (232, 234) of the GRIN lens protrude from opposite ends of the sleeve. The outer tube includes first and second receiving portions (252, 254). The ferrule is glued into the first receiving portion, and the sleeve is secured in the second receiving portion. A plurality of soldering holes (256) is defined in a periphery of the outer tube. Soldering is applied to the sleeve through the holes to firmly connect the outer tube and the sleeve together. A position of the GRIN lens relative to the optical fiber can be easily readjusted by re-soldering the sleeve.

Abstract: An optical fiber collimator (100) in an optical system, includes a pair of optical fibers (108) having emitting cleaved planes (112) to provide a substantially uniform angled side surface for forming a prescribed angle (101) relative to the optical axis (105) of the optical system. The pair of optical fibers (108) are disposed coplanarly in the object plane of the optical system for sharing the optical axis and separated from each other and from the optical axis on the same object plane. Optically coupled to the pair of fibers, a microlens (106) has a sloped rear surface (114) opposite a rotationally symmetric microlens surface (116) which bound a volume having a homogeneous index of refraction. The pair of fibers (108) are positioned near the focal plane containing the optical axis (105) of the microlens for the generation or reception of collimated beams at the prescribed angle (101) relative to the optical axis (105) of the microlens (106).

Abstract: An optical collimator (20) includes an optical fiber (21), a metal ferrule (22), a Graded Index (GRIN) lens (23) and an outer metal tube (24). The optical fiber has an exposed end (211) which is coated with metal. The exposed end of the optical fiber is inserted into the ferrule and laser welded thereto. The GRIN lens is also coated with metal. A plurality of soldering holes (241) is defined in a periphery of the outer tube. Solder is applied to the ferrule and the GRIN lens through the holes to firmly connect the outer tube, the ferrule and the GRIN lens together. After assembly, if the position of the GRIN lens or the optical fiber is found to be inaccurate, the GRIN lens and the ferrule can be easily resoldered.

Abstract: A fiber optic assembly includes a multi-port fiber optic device (100) with a buffer (200) circumferentially mounted thereon. A metallic foil (300) with the sealant (400)coated thereon, wraps around the buffered multi-port fiber optic device, and is crimped at two opposite longitudinal ends thereof. Both the buffer (200) and the sealant (400) are cured for reinforcement of the whole package assembly.

Abstract: An optical multiplexing/demultiplexing device with variable branching ratio is disclosed. The device includes a first collimator lens assembly having a first collimator lens 14, and first and second optical fibers F1 and F2 which have distal ends thereof optically coupled to the lens, and are away from each other by a distance “d,” an optical axis of the lens being positioned at a midpoint therebetween, a second collimator lens assembly having a second collimator lens 15 and a third optical fiber F3 which has a distal end thereof optically coupled to the lens, being away from an optical axis of the lens by a distance “d/2” and reflection mirror means. The reflection mirror means reflects and couples a part or all of a parallel beam of an expanded mode field area, which is emitted from the first optical fiber and formed on a reference plane, to the second optical fiber, or transmits and connects all or a part of the parallel beam to the third optical fiber.

Abstract: A light receiving module and a light receiving method to reduce polarization dependence, used in evaluation of polarization characteristics of various optical parts. The light receiving module has an optical mechanism including a first light transmission plate and a second light transmission plate between a first lens and a second lens, and a light receiving element of the outside of the optical mechanism. The first light transmission plate is inclined at such an angle as to have the same value as polarization dependence due to the inclination of the light receiving surface of the light receiving element, and subsequently the first light transmission plate is rotated by 90° in relation to the optical axis.

Abstract: A non-imaging optical coupler that is a figure of revolution combining a light-transmitting body defining a recessed input cavity, a transparent droplet-shaped encapsulant of a light-emitting diode, or array of diodes in the cavity, the body having a curved side wall shaped to totally internally reflect all the light emitted from the LED and encapsulant, traveling toward the side wall, within a predetermined distance from the diode or center of array, the body having a cylindrical transition section extending from a curved side wall and forwardly, and a planar exit face at the forward end of the body, transverse to the central axis of the figure of revolution.

Abstract: The present invention, generally speaking, provides compact design of optical couplers for combining two differently polarized light beams onto a collimator or splitting a composed light beam into two differently polarized light beams. According to another embodiment, the size of the polarization beam combiner is minimized by using a pair of specially designed fiber collimators that use an asymmetrical sleeve. As a result, a coupler, according to the present invention, uses less components, is of small in size and provides an easy-aligning structure. Further the coupler offers lower optical insertion loss with minimized physical size.

Abstract: An aspherical rod lens converts light emitted from a predetermined light source or an emittance end of an optical fiber into predetermined light, the aspherical rod lens has

Abstract: An optical isolator includes a first optical collimator, a first birefringent crystal, a Faraday rotator, a second birefringent crystal and a second optical collimator. The first and second collimators have the same structure and configuration. Each first and second collimator includes a ferrule, an optical fiber retained in the ferrule, and a collimating lens, all of which are secured in a tube. The first and second birefringent crystals are respectively fixed to the first and the second collimators. The Faraday rotator is stationed between the first and second collimators, and fixed onto an end of the first collimator. In assembly, the first and second collimators and the Faraday rotator are all secured in a stainless steel outer tube. The second collimator is rotated within the outer tube until correct relative alignment of optical axes of the birefringent crystals is attained.

Abstract: The present invention provides an optical signal add/drop apparatus comprising: an optical signal multiplexing/demultiplexing portion comprising a plurality of 2×2 channel unit devices which are arranged in a straight line and having first and second dual-core ferrules having two optical fibers disposed to be symmetrical to each other at an identical distance from an optical axis for transmitting optical signals, a wavelength division filter disposed between first and second lenses for selectively transmitting or reflecting only the optical signals having specific wavelengths, first and second grin lenses for collimating or focusing the optical signal transmitted or reflected from said wavelength division filter and then transmitting the signal to the first and second dual-core optical fibers; and a switch module having unit 2×2 switches connected to two optical fibers of the second dual-core ferrule of each of the unit devices of said optical signal multiplexing/demultiplexing portion; wherein th

Abstract: The present invention consists of a method and a structure formed by such method relating to optical fibers. Specifically, the invention consists of a chemical mill process for shaping the end of a fiber and thereby simultaneously forming both lens and precision mounting region. Also described is a self-aligning structure with integral lens. Both features improve light coupling. The lens focuses light energy entering and exiting the fiber. The precision mounting region facilitates alignment of fiber at couplings.

Abstract: An optical connector system is disclosed which utilizes a pair of substrates having optical elements associated therewith. Fiducial features in conjunction with alignment members are further utilized to provide for a greater alignment of the optical elements. Methods for forming the optical connector system are also provided.

Abstract: A structure facilitating easy assembly of fiber-optic communication components includes a lower and an upper support being provided with small and big V-shaped cuts, respectively, for receiving optical fibers and collimators, respectively. The upper support is inverted to seat on a middle recess of the lower support, such that tangent planes passing top points of the optical fibers and the collimators are contained in horizontal planes passing openings of the small and the big V-shaped cuts, respectively, and axes of the collimators are either in alignment with or horizontally coplanar with axes of the optical fibers. The two supports together define a central positioning cavity between them for receiving different function elements, such as optical isolator, modularized filter, etc., between the collimators, so that fiber-optic communication components with reduced volume and increased reliability could be easily assembled in mass production at reduced cost.

Abstract: An optical fiber collimator which facilitates optical adjustment. The optical fiber collimator includes a gradient index rod lens, and an optical fiber optically connected to the rod lens. An anti-reflection film is formed on one end face of the rod lens. The anti-reflection film has a refractive index which continuously changes from a value substantially equal to that of a center refractive index of the rod lens to a value substantially equal to that of the refractive index of the optical fiber along a film thickness direction of the anti-reflection film. A refractive index matching medium having a refractive index substantially equal to that of the optical fiber bonds the anti-reflection film to the end face of the optical fiber.

Abstract: A method and system for providing a dense wavelength division multiplexer is disclosed. The method and system include providing a dual fiber collimator, a filter and a filter holder. The dual fiber collimator includes a lens and a capillary. The capillary is for holding a plurality of fibers. The filter holder has an aperture therein. The filter is disposed between the dual fiber collimator and the filter holder. The filter has a first surface and a second surface opposite to the first surface. The first surface is covered with a filter coating. The filter is affixed to the filter holder by the second surface.

Abstract: This invention provides a novel wavelength-separating-routing (WSR) apparatus that uses a diffraction grating to separate a multi-wavelength optical signal by wavelength into multiple spectral channels, which are then focused onto an array of corresponding channel micromirrors. The channel micromirrors are individually controllable and continuously pivotable to reflect the spectral channels into multiple output ports. As such, the inventive WSR apparatus is capable of routing the spectral channels on a channel-by-channel basis and coupling any spectral channel into any one of the output ports. The WSR apparatus of the present invention may be further equipped with servo-control and spectral power-management capabilities, thereby maintaining the coupling efficiencies of the spectral channels into the output ports at desired values.

Abstract: Techniques and devices that optically couple multiple pump fibers and a signal input fiber to a double-clad fiber with a high coupling efficiency.

Abstract: An optical fiber structure for demultiplexing/multiplexing includes a coupler which splits an incoming signal with multiple channels into two substantially identical signals that are respectively processed to separate the closely located successive channel groups for further demultiplexing or multiplexing. The spectrum characteristics to process the two identical signals are so chosen that the channel distortion and/or transmission loss are minimized. In particular, multiple stages of splitter filters are used to shorten the transmission path a channel signal has to pass through. As a result, signal distortion and/or transmission loss are minimized and the channel groups are interleaved by a single channel group.

Abstract: The invention provides an optical coupling system having first and second back-to-back GRIN lenses each having an input and an output end face, an optical filter element disposed between the first and second back-to-back GRIN lenses, an input optical fiber tube having two optical fibers therein adjacent to and optically coupled with the first of the back-to-back GRIN lenses, an output optical fiber tube having an optical fiber therein adjacent to and optically coupled with the second of the back-to-back GRIN lenses, wherein an inwardly facing end face of the output optical fiber tube and the output end face of the second of the back-to-back GRIN lenses are non-parallel to each other for reducing coupling losses. The optical coupling system is supported in glass holding tubes.

Abstract: A GRIN fiber lens has a silica-glass core whose refractive index has a radial profile. The profile has a radial second derivative whose average magnitude in the core is less than about 1.7×10−6 microns−2 times the value of the refractive index on the axis of the GRIN fiber lens.

Abstract: An improved highly doped waveguide is provided which comprises a waveguide employing an Er dopant and Pr sensitizer ions. The present invention also provides a method of efficient coupling from an optical source into a waveguide using a rotated optical element.

Abstract: An optical collimator for WDM application. Preventing the adhesive material from blocking the light path, the optical collimator includes a glass ferrule with a hole, at least one optical fiber grasped by the glass ferrule, a GRIN lens having two end surfaces, with one end surface of the GRIN lens combined with the glass ferrule, and a filter combined with another end surface of the GRIN lens. At least one pad with an opening is sandwiched between the filter and the GRIN lens, and, using a thermal-curing epoxy, the pad adheres to the GRIN lens and the filter adheres to the pad.

Abstract: A receptacle type optical module including a lead frame having a plurality of leads, an L-shaped block mounted on the lead frame and having a through hole, a ferrule inserted and fixed in the through hole of the L-shaped block and having an optical fiber, a carrier mounted on the L-shaped block and having a wiring pattern, and an optical element mounted on the carrier. The optical module further includes a GRIN lens fixed to an end face of the ferrule and having a spherical end face adjacent to the optical element, a transparent resin for sealing an optical coupling portion between the optical element and the GRIN lens, and a resin molded package for encapsulating all of the lead frame, the L-shaped block, the ferrule, the carrier, and the optical element except a part of the lead frame and a part of the ferrule.

Abstract: A system and method for wavelength division multiplexing and demultiplexing with broadened and flattened passband profiles are disclosed. A spectral modifying element may be used to broaden and flatten the passband profile of associated multiple wavelength optical signals and spectral components. The system preferably includes a light focusing device and a diffraction grating having a direction of dispersion. The spectral modify element primarily transforms or broadens and flattens optical signals in only the direction of dispersion of the associated diffraction grating.

Abstract: A liquid crystal cell assembly is described which eliminates high-order multiple-beam interference from reflections at the interfaces between the various elements. It can incorporate fixed retarders for compensation or production of high retardances. The invention enables standard, economical methods to be used in making the liquid crystal cell, retarder elements, optical coatings, and overall assembly. Transmissive and reflective embodiments are shown.

Abstract: A retro-reflective multi-port fiber optic device includes the triple-fiber ferrule with a GRIN rod lens to couple the light. The triple-fiber ferrule with three fibers thereof is attached to the angled facet of the GRIN rod lens and the WDM filter is attached to the opposite side of the lens. A reflective mirror is aligned with and attached next to the other side of the WDM filter opposite to the lens. The triple-fiber ferrule, which is specifically selected from adense series of triple-fiber ferrules respectively defining three-fiber assemblies with different fiber spacings, is used to couple light in and out of the device, and tune the filter center wavelength to the desired ITU grid.

Abstract: A novel array of optically and electrically interacting optical MEMS dies physically and electrically integrally attached upon an optically transmissive preferably (transparent) printed circuit substrate that is monolithically formed with one or more optical components, such as lenses, for providing fixed optical path alignment and interaction therebetween, and with provision for the integration also of active optical components such as lasers and photodiodes and the like.

Abstract: A V-groove dual fiber DWDM collimator (1) including an optical lens (10) and a V-groove dual fiber ferrule means (12) fixed with each other. The ferrule means (12) includes a V-groove chip (14) and a cover chip (20) commonly enclosed by a protective guiding sleeve (22) wherein two pigtail fibers (24, 26) are respectively received within the corresponding grooves (16) of the V-groove chip (14). The V-groove ferrule means (12) is itself fixed by adhering its own internal components (14, 20, 22) and the embedded fibers (24, 26), and also fixed to the lens (10).

Abstract: A multilayer optical fiber coupler for coupling optical radiation between an optical device and an optical fiber, including a first layer that has a fiber socket formed by photolithographic masking and etching to extend through said first layer, and a second layer bonded to the first layer. The first layer may comprise substantially single-crystal silicon. An optical fiber is inserted into the fiber socket to align the optical fiber precisely within the fiber socket. In one embodiment the optical fiber is a single mode fiber, and an optical focusing element formed on the second layer is aligned with the core of the single mode fiber. The second layer may comprise glass having an index of refraction that approximately matches the index of the optical fiber, and an optical epoxy is used to affix the optical fiber into the fiber socket and fill the gaps between the end face of the fiber and the second layer.

Abstract: In an optical system in which light output from an optical fiber (11) is collimated into parallel light rays by a gradient index rod lens (13), reflected by a filter (4) and then converged again by the rod lens (13) so that the resulting light is coupled to an optical fiber (12), a principal beam component of the light output from the optical fiber (11) disagrees with an optical axis (32) of the optical fiber (12) to thereby cause a coupling loss.

Abstract: An apparatus includes an optical element, a GRIN lens, and a detector. The optical element has a first optical aperture. The GRIN lens has first and second ends. The first end of the GRIN lens is positioned to receive light from the first optical aperture. The detector is configured to measure values of a characteristic of light emitted from the first end in response to multi-photon absorption events in a sample illuminated by light from the second end of the endoscopic probe.

Abstract: An optical module which satisfies a required insertion loss and can be easily assembled with high productivity. The optical module includes first optical fiber, a first lens, an optical device, a second lens, and second optical fiber. The first lens receives an incident light from the first optical fiber and converts the incident light into a parallel light. The optical device receives the parallel light and performs predetermined optical processing on the parallel light. The second lens receives a transmitted parallel light from the optical device and converge the transmitted parallel light to produce an outgoing light. The second optical fiber receives the outgoing light. An optical axis of the first lens and an optical axis of the second lens are substantially coincident with each other. An optical axis of the first optical fiber and an optical axis of the second optical fiber are substantially parallel with each other and substantially parallel to the optical axes of the first and the second lenses.

Abstract: There are provided an optical fiber having a light focusing function and capable of setting the distance WD to the beam waist position and the beam waist diameter &ohgr; independently, and a method of manufacturing the optical fiber efficiently and at high accuracy. An end surface of a single mode optical fiber is connected to one end surface of a very short piece of spacer constituted of an optical fiber the diameter of which is identical to that of the single mode optical fiber and the refractive index of which is uniform. The other end surface of the spacer is connected to one end surface of a very short piece of graded index optical fiber the diameter of which is identical to that of the single mode optical fiber and the refractive index of which varies continuously in the direction of its diameter.